Processing and manufacturing method for accurately exposing copper in step groove of multi-layer circuit board

Abstract

The invention discloses a processing and manufacturing method for accurately exposing copper in a step groove of a multi-layer circuit board. The processing and manufacturing method comprises the following steps: step 1, manufacturing the multi-layer circuit board; 2, a blind groove is machined; 3, a through groove is machined; and step 4, forming the step groove. According to the method, the blind groove is firstly machined, the dielectric layer is reserved between the groove bottom and the bottom copper, then the mechanical through groove is machined, the blind groove is continuously machined through the laser drilling machine until the bottom copper leaks out, and finally residual glue at the bottom of the step groove is removed through plasma, so that copper can be accurately exposed at the bottom of the step groove, and meanwhile the problems of burr and warping of a copper sheet at the bottom are solved; the device is high in practicability and has relatively high popularization significance.

Description

Technical Field

[0001] The invention relates to the field of printed circuit board manufacturing technology, and in particular to a processing and manufacturing method for accurately exposing copper in a step groove of a multi-layer circuit board. Background Art

[0002] Circuit boards can be called printed circuit boards or printed circuit boards. They are important electronic components, supporting electronic components and providing electrical connections for electronic components. Circuit boards include single-layer circuit boards and multi-layer circuit boards. Multi-layer circuit boards often have step grooves designed to expose copper at the bottom of the step grooves because they need to connect components, so as to achieve the purpose of connection and conduction.

[0003] Conventional step groove processing methods are mostly to first drill a mechanical through groove, then measure the required depth of the step groove by slicing, and then use a mill to fix the depth to process the step groove. However, because the dielectric layers and copper thickness of multi-layer circuit boards have a certain fluctuation range, this processing method cannot accurately expose the copper at the bottom of the step groove, which can easily affect the electrical connection between the multi-layer circuit board and electronic components, and ultimately cause the circuit board to malfunction. Summary of the invention

[0004] Based on this, it is necessary to provide a processing and manufacturing method for accurately exposing copper in step grooves of multi-layer circuit boards in response to the deficiencies in the prior art.

[0005] A method for processing and manufacturing a step groove of a multi-layer circuit board to accurately expose copper, comprising the following steps:

[0006] Step 1: Making a multi-layer circuit board, first designing and making a multi-layer circuit board, the multi-layer circuit board is formed by a plurality of copper layers and dielectric layers being alternately laminated in sequence, and the multi-layer circuit board is also provided with a through groove processing position and a step groove processing position, the step groove processing position is arranged adjacent to the through groove processing position;

[0007] Step 2: Processing a blind groove, first processing a blind groove at the step groove processing position, and retaining a dielectric layer at the bottom of the blind groove;

[0008] Step 3: Processing a through groove, processing a through groove at the through groove processing position, wherein the through groove passes through two sides of the multi-layer circuit board and is connected with the blind groove;

[0009] Step 4: Step groove forming: the blind groove is processed again by laser drilling to remove the dielectric layer retained at the bottom and expose the copper layer to form the final step groove.

[0010] Furthermore, in step 2, the thickness of the dielectric layer retained at the bottom of the blind groove is 0.1 mm to 0.15 mm.

[0011] Furthermore, in step 2 and step 3, the blind groove and the through groove are processed by mechanical drilling.

[0012] Furthermore, after step 4, the residual glue residue in the step groove is cleaned by plasma cleaning.

[0013] In summary, the beneficial effect of the processing and manufacturing method of the step groove of a multi-layer circuit board of the present invention for accurately exposing copper is that by first processing the blind groove, retaining the dielectric layer between the groove bottom and the bottom copper, then processing the mechanical through groove, and then continuing to process the blind groove with a laser drill until the bottom copper leaks out, and finally plasma cleaning the residual glue at the bottom of the step groove, the bottom of the step groove can be accurately exposed to copper, and the problem of the bottom copper skin flaring and warping can be avoided; the practicality of the present invention is strong and has a strong promotion significance. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The cross-sectional structure diagram of the process from step 1 to step 4 in a method for processing and manufacturing a step groove for accurately exposing copper in a multi-layer circuit board of the present invention. DETAILED DESCRIPTION

[0015] In order to further understand the features, technical means and specific objectives and functions achieved by the present invention, and analyze the advantages and spirit of the present invention, a further understanding is obtained through the following detailed description of the present invention in combination with the accompanying drawings and specific implementation methods.

[0016] like Figure 1 As shown, the present invention provides a method for processing and manufacturing a step groove of a multi-layer circuit board with precise copper exposure, comprising the following steps:

[0017] Step 1: manufacturing a multi-layer circuit board 100, first designing and manufacturing a multi-layer circuit board 100, wherein the multi-layer circuit board 100 is formed by a plurality of copper layers 10 and dielectric layers 20 being alternately laminated in sequence, and the multi-layer circuit board 100 is further provided with a through groove processing position 30 and a step groove processing position 40, wherein the step groove processing position 40 is disposed adjacent to the through groove processing position 30;

[0018] Step 2: Processing the blind groove 50, using a mechanical drill to first process a blind groove 50 at the step groove processing position 40, and retaining a dielectric layer 20 with a thickness of 0.1 mm to 0.15 mm at the bottom of the blind groove 50;

[0019] Step 3: Processing a through groove 60 , using a mechanical drill to process a through groove 60 in the through groove processing position 30 , wherein the through groove 60 passes through both sides of the multi-layer circuit board 100 and is connected with the blind groove 50 ;

[0020] Step 4: The step groove 70 is formed, and the blind groove 50 is processed again by laser drilling to remove the dielectric layer 20 retained at the bottom and expose the copper layer 10 to form the final step groove 70; after the step groove 70 is formed, the residual glue residue in the step groove 70 is cleaned by plasma cleaning.

[0021] In summary, the beneficial effect of the processing and manufacturing method of the step groove of a multi-layer circuit board of the present invention for accurately exposing copper is that: by first processing the blind groove 50, retaining the dielectric layer 20 between the groove bottom and the bottom copper, then processing the mechanical through groove 60, and then continuing to process the blind groove 50 with a laser drill until the bottom copper leaks out, and finally plasma cleaning the residual glue at the bottom of the step groove, the bottom of the step groove can be accurately exposed to copper, and the problem of the bottom copper skin being flared and warped can be avoided; the practicality of the present invention is strong and has a strong promotion significance.

[0022] The above-mentioned embodiment only expresses one implementation method of the invention, and its description is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the inventive concept, which all belong to the protection scope of the invention. Therefore, the protection scope of the invention patent shall be based on the attached claims.

Claims

1. A method for processing and manufacturing a step groove of a multi-layer circuit board to accurately expose copper, characterized in that: The steps include: Step 1: Making a multi-layer circuit board, first designing and making a multi-layer circuit board, the multi-layer circuit board is formed by a plurality of copper layers and dielectric layers being alternately laminated in sequence, and the multi-layer circuit board is also provided with a through groove processing position and a step groove processing position, the step groove processing position is arranged adjacent to the through groove processing position; Step 2: Processing a blind groove, first processing a blind groove at the step groove processing position, and retaining a dielectric layer at the bottom of the blind groove; Step 3: Processing a through groove, processing a through groove at the through groove processing position, wherein the through groove passes through two sides of the multi-layer circuit board and is connected with the blind groove; Step 4: Step groove forming: the blind groove is processed again by laser drilling to remove the dielectric layer retained at the bottom and expose the copper layer to form the final step groove.

2. The method for processing and manufacturing a step groove of a multi-layer circuit board with accurate copper exposure as claimed in claim 1, characterized in that: In step 2, the thickness of the dielectric layer retained at the bottom of the blind groove is 0.1 mm to 0.15 mm.

3. The method for processing and manufacturing a step groove of a multi-layer circuit board with accurate copper exposure as claimed in claim 1, characterized in that: In step 2 and step 3, the blind groove and the through groove are processed by mechanical drilling.

4. The method for processing and manufacturing a step groove of a multi-layer circuit board with accurate copper exposure as claimed in claim 1, characterized in that: After step 4, the residual glue residue in the step groove is cleaned by plasma cleaning.

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